Speed change transmission



ug- 15,- 1950 E. E. WEMP 2,518,734

SPEED CHANGE TRANSMISSION Filed Nov. 15, 1944 3 Sheets-Sheet 1 INVENTOR.7a zfIP/wsrf /r/01P M 10. 1 2 .104. iv lw I; 21%

s- 15, 1950 E. E. WEMP 2,518,734

SPEED CHANGE TRANSMISSION Filod Nov. 15, 19M 3 Sheets-Sheet 2 55- III/aINVEN TOR.

i 3 J ex [575M97 I BY Aug. 15, 1950 EIE. WEMP 3,

SPEED camera mnsuxssxon I Filed Now-15. 1944 a Sheets-Sheet s arrow/5yPat nted ug. 15,1950

2,518,734 I SPEED CHANGE TRANSMISSION Ernest E. Wemp, Detroit, Mich.,assignor of :flve

per cent to Eleanor May Wemp, Los Angeles, 'CaliL, five per cent toIleah Kathleen smith, five per cent to Clyde J. .Smith and twenty,

- per cent to Lila A. Wemp, all of Detroit, Mich.

ApplicationNovember 15, 1944, Serial No. 563,482

I 1Claim. 101492-53)" This invention relates to a transmission forproviding a number of gear ratios between driving and driven members.

one adapted. for use in an automotive vehicle and such use maybevisualized as the invention is described. The transmission, of course,may

be .used in other places.

In general, the objects of the invention are to The transmission is Fig.7 is a view showing the detail of the blocker element of the powercoupling.

Fig. 8. is a detailview showing the synchronizing and blocker element ofa synchronizing provide an improved transmission capableof being easilyoperated and, indeed, one which lends itself to automatic or a,semi-automatic manner of operation. In this connection, the transmissioninvolves a pluralityof shiftable elements for coupling.' a

Fig. '9 is a developed section taken substantially on line 9-9 of Fig.2showing blocker elements ofthe power coupler.

Fig. 9a is a view similar to Fig. 9 showing the blocker elements ina'different position.

Fig. 10 is a developed view taken substantially on line .lO--lll of Fig.3 showing blocker elements of'the synchronizing coupling.

effecting different gear ratios which function in conjunction with eachother. able elements is in the nature of a conventional shifting elementas 'is presently used in transmissions for establishing drivingconnections through different gears or gear sets. Another of theshiftableelements is What maybe termed a power coupling shiftable toconnect different gears or gear sets and the power coupling is one whichis operable while the two members which are to be connected by a dental.engagement are under torque load. A further object of the invention isto provide a transmission which will not be excessive in cost and whichindeed may have a relatively low cost. In this'connection, as will beseen later, an' adequate number of speed ratios both forward and reverseis provided witha' minimum number of gears.

Other objects of the invention will be appreelated as the detaileddescription is followed in conjunction with i the accompanying drawings.

These drawings show one form ofmechanism for 5 carrying outthe'invention.

Fig. 1 is a sectional view taken through a transmission constructed inaccordance with theinvention, showing the same in a neutral position andillustrating the reverse gear shaft swung to a position whereit can beseen.

Fig. 2 is apsectional view taken substantially on line 2 2 of Fig. 1illustrating the control for the power coupling.

Fig. 3 is a sectional view taken substantially on line 3-4 of Fig. 1showing the control for the synchronizing type of coupling.

Fig. 4. is a sectional view taken substantially on line 44 of Fig. 3showing the control mechanism for the forward and reverse gear.

Fig. 5 is an enlarged sectional view-showing the power coupling in oneconnected position.

Fig. 6 is an enlarged sectional view showing the synchronizing shiftingelement in one Collpled condition.

One of the shift 16 is illustrated at I2.

Fig. 10a is a view similar to Fig. 10 showing the blocker elements in adifferent position.

- Fig. 10b'is a view similar to Figs. 10 and 10a showing the blockerelements in still a different position. v

Fig. 11 is a view showing the internal toot construction on one of thegears.

The transmission, as shown in Fig, l, is provided with a suitablehousing I. The power input shaft is illustrated at 2.

This may be a clutch shaft driven by an internal combustion engine. Thepower output membe is generally illustrated at 3 there being asuitableterminal piece 4 thereon which may constitute apart of auniversal joint assembly. Secured to the out- Y put nie'mber3 may be aworm gear 5 for. driving a shaft 6 to provide a power take-off for aspeedometer or other device.- The input member is suitably 'journalledin the housing. as by means of a bearing I while the output member issuitably journalled in a bearing 8.

' Inthe constructionshown in'Fig. l the power input or driving member 2projects into a sleevelike part of the power output or driven member 3and the two members are associated with each other as by means of needlebearings Hi and II, and the sleeve-like part of the output member IRotatably mounted upon the shaft 2, as by means of needle bearings I3 isa gear l4 having an 'extension with a conical exterior surface l5 andinternal teeth I 6. gear 20 is rotatably mounted on the shaft 2 as bymeans of needle bearings 2| and this gear has an extension with aconical exterior, shown at- 22, and which is provided with internalteeth 23. Secured to the gear 20 is a ring 24 having an internalfrictional face as illustrated.

Rotatably mounted upon the driven member 3 is a gear 28. Secured to thegear 28 is a ring 29 with an internal friction face. A suitable bearing30 may be-used for mounting the gear 28.

There is asplined counter shaft journalled in the housing as at 88a and81a and upon this shaft is a gear 88 and a gear 81. These two gears maybe formed from an integral piece as illustrated. The teeth of gear 88mesh with the teeth of gear I 4 and the teeth of gear 81 mesh with theteeth'of the gear 28. Another gear 48 is disposed on the shaft}! so thatit can be axially shifted and this gear has a groove 4| for receiving-ashifter member. There is a shaft 42, which may be termed a reverse gearshaft, mounted in the housing and 'journalled upon which is a doublegear element having a gear 43 and a gear 44. This elementmay bejournalled bynee'dle bearings 48. As shown in Fig. 1-, the-reverse gearshaft 42 and the gear element 48 thereon are swung out of position sothat they can readily ,be seen. But, it is to be understood that theteeth of' gear 44 mesh constantly with the teeth of gear 28. This willbe appreciated by reference to Fig. 3 where the several shafts are shownin their correct relative positions.

This gearing arrangement, as shown, -is arranged to provide fourspeedsforward and two speeds in reverse. Suitable shiftable means forestablishing dental en agements are provided for this purpose but beforeproceeding with a description of this means it is thought that thematter would be clarified by tracing the various operating paths throughthe transmission. For

first or low speed: The drive shaft 2 is cou led to the gear 14 which,through gear 88, drives co ntershaft 85; the teeth of gear 48 are meshedthe output or driven shaft 8. For second s eed: The drive shaft iscoupled to gear 28 which, through. gear. 81. drives countershaft 85 andgear 48 thereon is enga ed with gear 28 whichis cou-' pled to th drivens aft 3. For third speed;

driven shaft 8. The couplerv 84 is axially shiftable on the splines.Suitable control means may be. attached to the element 88 for operatingthe same. The gears 28 'and 28 are provided with teeth 88 and 81arranged to be dentalh! en a ed selectively by the splines on thecoupler 84. In Fig. 1 the coupler 84 is in a neutral position where itdoes not engage either gear 28 or gear 28. In Fig. 6 the coupler hasbeen shifted to engage with the gear 28. The splines 88 and'the teeth 88and 81 are preferably straight.

A synchronizing member slidably fits over I -the coupler 84; ,Thissynchronizer is of a'spider v and I4 for frictionally engaging thein'ternalsurfaces of the members 24 and 28. Therefis a with those ofgear 28 and ear 28 is coupled with teeth constantly in m sh, and gear 28is couable control element 82 with a crank arm 88 connected to theshiftable element 88. The shiftable element has a fork 84 slidablyengaging a stabilizing rod and a shoe 88 enga ing the groove 4!. Adetent arrangement residing in a spring pressed plunger 58' and threenotches 81 in the rod 5| holds the gear 0, in am) one of threepositions. As shown in Fi s. 1 and 4 the -gear 48 is in neutralposition. When shifted to the right as Fig. 1 is viewed, the gear 48dentally engages the gear 28 and when shifted to the left it dentallyengages the gear 43. Any suitable 12 in the' flange of the coupler.

construction with a full ring-like section at one end and with fingers'll projecting through slots nizing member has tapered or coned surfacesI8 frictional engagement between the coupler and the synchronizingmember provided by two expanding springs 18 disposed in recesses in thecoupler and expandinginto frictional engagement with the synchronizingmember 18. When the coupler 84 is shifted to the left as Fig. 1 isviewed, the surface 18 frictionally engages the member 24 and therebytends to synchronize the speed of'rotation of the gear 28 and the drivenshaft 8.

In making the dental engagement the coupler 84 slides frictionallywithin the synchronizing member 18. ,Fig. 6 shows the coupler .84coupled to the gear 28 with the splineson the coupler and the teeth 88in dental engagement.

When the coupler 84 is moved to the right, as Fig..

1 is viewed, the surface 14 engages the member 28 and synchronizes thegear 28 to the speed of rotation of the shaft 3. When the coupler is soshifted to the right the splines on the coupler dentally engage with theteethv 81 and thereby cou le the gear -28 to the driven shaft. Normally,the synchronizing element I8 is arranged to have a running clearancejwith the members 24 and 28. It will be understood that when the coupleris in the position shown inFig. 6 the gear 28 is coupled to thedrivenshaft, and that when it is shifted to the right as Fig. 1 is viewed, thegear 28 is coupled to the driven shaft.

There is a blocking arran ement efi'ected'by an interengagement betweenthe arms 'H of the synchronizing element and the coupler 84. As

shown in Fig. 8, the arms H are provided with recesses on opposite facesas shown at "15 and II. The metal defining the openings in the flange 88I is suitably shaped to provide inter-engaging porcontrol meanspositionedfor convenient manipulation may be connected to the member 82.

The means for selectively coupling the gears 28 and 28 to the drivenshaft is shown in Figs. 3 and 6. A controlling element has a crank arm8| with a shoe 82 associated with the flange 83 of a shiftable coupler84 which has a splined connection as at 85 with the sleeve portion I2 ofthe tions 11 and 18 for lockiwzly engaging in the recesses. Thedifferent positions are shown in Figs. 10, 10a, and 10b, and thesepositions are obtained by the relative rotary motion of the parts.

As above described, it will be remembered that in the second speed ratiothe gear 28 is coupled to the drive shaft2 and the gear 28 is coupled toI the driven shaft 8 through the inter-engagement of the splines on thecoupler 84 with the teeth 81 and the splines on the driven shaft. Thetorque is transmitted through gear 28, gear- 81, gear 48 to gear 28, anddue to the gear reduc-- tion. the gear 28 is rotating faster than gear28.

When a shift is made to the third speed ratio gear 28 is released fromthe driving shaft and v the coupler 84 is moved to uncouple the gear 28and to couple the gear 28 to the driven shaft.

When the coupler 84 is shifted to release gear 28,

and is in the intermediate position as shown in This synchro- Fig. 1,the gear 2'0 is rotating faster than gear 20 and, therefore, fasterthan-the coupler 64 and the synchronizing element 10. As Fig. 3 isviewed, the rotation ofthe shaft 2 is counterclockwise. As thesynchronizing element comes into frictionalengagement .with the, part 24it -moved clockwise relative to the coupler 84. This, as depicted inFig. 10, causes the synchronizing element I to move upwardly, as Fig. isviewed, and when the coupler 64 speed of relative rotation. Thesefactors can be so organized that a dental engagement is finallymadeuponthe synchronizing of theparts so that a silent dental engagementmay be effected.

The coupler situated'between the gears I4 and 20 .is a different type ofcoupler and is one" which may be called a power coupler, in that it maybe coupled to driving and driven members rela-' becomes centrallydisposed or, in other words,'in V neutral position as shown in'Fig. l,the blocking edge 11 will shift into the notch 15. This conditionwillcontinue so long as there is different relative rotation and,accordingly, the coupler 04 is'blocked and cannot move further to theleft.-

.This holds the coupler in the'neutral position shown in. Fig. 1. Butgear 20 has been released from the drive shaft and the .frictionalengagement between the part 24 andthe,surface .13 is decelerating thegear 20. When it decelerates tively while both are under torque load.-The shifter element or coupler is illustrated at-80 and This couplerhasa splineconnection 82 with the driving shaft 2. These splines arestraight and the coupler may shift 23 on the gear 20, and a set of teeth85 for dental axially thereon! The coupler has a set of'teeth 83 forengagement with the set of internal teeth 1 engagement with the set ofinternal teeth I6 on the gear I4.

There is a blocking element positioned overthe coupler. This elementisshown in Fig. 7, hasa ring-like body 90 with an internal face which to apoint where it is substantially synchronized:

with the driven shaft-and, therefore, thecoupler 64, there is norelative motion andzthe parts'are I tion shown in Fig. 10b. At thismoment, the

axial movement of the coupler 64 may be continued to complete 'thedental engagement'with the gear 20. When a shift is to be posite. Inother words, the gear 28 is rotating-at a lower speed than gear and,therefore, a lower speed than the coupler 64 and the syn-- chronizer 10.Accordingly, when-the synchronizer engages the element .29 it is rockedclockwise relative to the'coupler 64 and, as Fig. 3 is viewed, and asillustrated in Fig. 10b, there is an interengagement between the notchesI6 and blocking edges 18. This prevents further shift of the couplerelement until the coupler element 64 and the gear 28 are substantiallysynchronized so that there is substantially no relative rotation at iwhich time the coupler element 64 may be shifted to the right. toestablish a connection with the teeth 61 of the gear 28.

In both instances, that is in both directions of shift. it will beobserved that the shiftable coupler is blocked in a neutral positionbecause of a blocking action incident to and caused by relative rotationof the parts about to be dentally engaged. When the parts becomesubstantially synchronized, however, the blocking action ceases so thata coupling may be established. A number of factors necessarily play apart in this operation. These include the amount or extent of thefriction exerted by. the synchronizing element 10, the amount of theaxial load on the coupler 1 element 64 and the angularity of theinterengaging locking elements 15 and I! or 16 and I8, and the relativemovement of the parts about to be synchronized. 1 An increase in theaxial load on the coupler 64 increases the frictional load be,

tween the gear and synchronizing element 10 becauseof the inter-engagingblocking elements. The force with which the blockingelements are heldinteren-gaged is dependent somewhat on the frictional load between thesynchronizing element and the gear engaged thereby and by the made toestablish a." coupling with the gear 28 the action is the same. exceptthe relative direction of rotation is op--.

may be, provided withjsuitable friction material 9! for frictionallyengaging the part I5 of the gear'QM. LProjecting from the body arefingers 92-which extend through slots 84in the flange 81. -A ring, ofsuitable friction material, as shown at 05, is screw threaded upon theends of the fingers and held locked in' position and this ring has aninternal face for frictionally engaging thepart 22 of the gear 20.v

As shown in Figs. 7, 9, and 9a, eachlflnger 92 has a notch 96 shaped 'toreceive a cooperating edge 91 of the metal defining one side of the slot84, the function of which will be presently described. The shiftablecoupler 80 and the block- -ing element 90 are frictionallyassociatedthrough the means of an expanding spring I00 disposed in acircumferential groove II; and arranged to expand and frictionallyengage the internal peripheral surfaces of the member 90 and its fingers92. At its intermediate portion, the element 90 is provided with aninternal recess formation in which the expanding spring I00 engages,this recess or notch formation being illustrated at I02. As illustratedin Fig. 7, the intermediate portionof this member falls at a location ofthe fingers 92 and, therefore, in reality each finger has a notch I02although they function as one. On each side of the notch formation is aninternal axial surface I03 and I04.

When the coupling 80 and the synchronizing element 90 are relativelycentrally positioned, the expanding spring engages in the notchformation I02 and, of course, also lies partially' in the groove l0l.When the coupler 00 and the synchronizing element 90 are shiftedrelatively axially the expanding spring is partially collapsed as itmoves out of the-recess formation and is forced into the groove l0l andfrictionally engages against either the surface I03 or the sur face I04depending upon the-relative directionof shift. 7 The control for thepower coupler resides in a rock shaft H0 as shown in Fig. 2 which has anarm I I I coupled to a shoe I I2 which engages the Any suitableoperating element may beattached to the control H0 and disposed in aconvenient location.

The dentally engaging set of teeth and I6 and the dentally engaging setof teeth 03 and 23 are angularly disposed helically relative to eachother as shown in Figs. 5 and 1'1. The teeth of each group are similarlyformed and are chamfered so as to provide a relatively pointed or sharpedge H5 for facilitating the start of I the dental engagement.

with.

it on the gear I are shown in Fig. 11 and those on the gear 28 are ofsimilar construction. The

teeth 85' on the coupler element 88 have a left hand helical formationand the teeth If on the gear 14 are correspondingly made to interflttherewith. The teeth 88 have a right hand helical formation and theteethy23 on gear 28 are made to correspond and dentally engage there-The operation of this power coupler for selectively coupling the gear l4and the gear 28 to the drive shaft 2 operates as follows: First, it- Ywill be appreciated that when the teeth l8 and 85 are coupled that thegear I4 is coupled to the v drive shaft; when the teeth 83 and 28 arecoupled that the gear 28 is'connected to the drive shaft. In theintermediate or neutral position, shown in Fig. 1, there is noconnection and the expand 1 ing spring I88 rides'in the recess formationI82.

An axial force on the coupler 88 to the left places 1 an axial load tothe left on the synchronizing and blocking element 98 so that itfrictionally engages the portion l5 of the gear II. This is accomplishedby the spring I88. This axial load I on the member 98 is at its maximumas the spring rides out of the inclined wall structure of the recessformation. If an axial load is placed on the coupler to the right, themember 98 isurged to the right and the ring 95 frictionally engages theportion 22 of the gear 28. Eventually; the

coupler is shifted to the right and the spring rides out of the recessformation and engages the surface I88. It will be understood that theelement 98 has a suitable running clearance so that it can run free ofthe gears i4 and 28.

Consider, now, that the coupler 88 is connected to the gear it as shownin Fig. 5. In this condition, and with the shaft 2 transmitting thetorque to shaft 8, the coupler becomes a driving mem- I her and the gearIt a driven member. -The di- I rection of rotation is clockwise as Fig.5 is viewed.

from the left -Accordingly, torque delivered from the shaft'2 causes anaccepting tendency for the dentally engaging teeth l5 and 85.. In otherwords, it has a tendency to shift the coupling element 88 further to theleft. Upon torque reversal, by which we mean that the driven shafttransmits driving torque to the shaft 2, the helical formation of theteeth causes a tendency to reject or, in other words, places an axialload on the coupling element 88 tending to shift it to the right. Thehelical angle, however, is such that combined loads on the dentallyengaging teeth l8 and 85 and the loads on the splines 82 substantiallybalance the thrust which tends to break the dental engagement so thatthere is no disengagement upon this torque reversal.

When the throttle of the engine is cut so that there is a torquereversal, and an axial force is applied to the coupler through the.controllingelement H8, the coupler 88 is shifted to the right todisengage the teeth. I Thiscan occur only by some relative rotationbetween the gear I and the shaft 2 since the coupler rotates uniformlywith the shaft due to the straight splines 82, and the gear It must becaused to slightly overrun the coupler'as the helical teeth are slidingout of dental engagement. If this shift'is made when the parts 'are infirst speed, the gear .14. is cou- 22'of the gear 28 and the'ring 95oscillates the blocking element 98 relative to the coupler withther'esult that the locking edges 91 engage in the recesses' 9,8 asshown inv Fig. 9a and the coupler 88 is therefore locked in theintermediate position shown in Fig. 1. This condition will remain solong as the shaft 2 and the engine are rotating, lower thanthe spec ofrotation of the gear'28 as, for example, whe the-engine is near idlingspeed. Upon accelerationof the engine,

however, it first comes up to the speed of the gear 28 and then tends tooverrun the gear 2| and the synchronizing element 99 is shifted back toa condition shown in Fig. 9, thus disengaging the blocking elements 98and 91 as shown in Fig. 9.. At this moment, realizing that there is anaxial force to the right on the coupler 88, the

' coupleris free to move to the right and the teeth.

88 become dentally engaged with teeth 23. In this action the couplerteeth 'enter into engagement with the gear 28 with a'screw-like actionand shaft 2 slightly overruns the gear 28 during the time interval whenthe teeth are sliding into full dental engagement. When torque isdelivered from the driving member the angle of the teeth 83 and 23 tendto cause an acceptance or, in other words, place an axial load on thecoupling element 88 to the right; upon torque reversal the tendency isto reject or,.in other words. to shift the coupler to' the left but thisdoes not occur as it is substantially balanced and overcome'by thecombined loads by the dentally engaging teeth 23 and 83 and the splines82.

In considering the shift of'the coupler to. the

left, an axial force is placed thereon and it is I shifted to disengagethe teeth 23 and 83 and at this time it is rotating at a speed which islower than the speed of rotation of the gear l4. Accordihgly, thefrictional engagement of the member 88 with the part I5 causes theblocking element to inter-engage and lock as shown in Fig.9a. When thespeed of the engine and drive shaft 2 are accelerated so that they tendto overrun the gear It, or if the-gear ll decelerates tending tounderrun the shaft 2, the blocking arrangement shown in Fig. 9a isreleased and a condition exists as shown in Fig. 9. The cou'pler element88 may be shifted to the left to engage the teeth It and 85. As theteeth It and 85 are shifting gear 28, gear 51 and shaft 35, dependingupon whether the coupling member is connecting the shaft 3 with the gear28 or gear 28.

ple'd to the shaft through the gear 38, shaft 35, l

5 gear 48, gear 28 and the coupling provided by the teeth 65 and 51. Atthis time the gear 28 is be- It is thought to be well to repeat thedescription of the various gear ratios in the transmission in the lightof the operation of' both of the couplers. As shown in Fig 1, bothcouplers are in neutral. The first speed isestablished whenthe coupler88 is connected to the gear l4 and the coupler 64 is connected to thegear 26. Torque is then transmitted through the transmission by thefollowing elements: Shaft 2, coupler, gear 14, gear 36, shaft 35, gear40, gear 28, coupler 64, to shaft 3. The second gear ratio isestablished when the coupler 80 is connected to the gear 20 and thetransmission line is as follows: Shaft 2, coupler 80,- gear 20, gear 31,gear 40, gear '28, coupler 64 to shaft 3. The third speed is establishedwhen the coupler 80 is connected to the gear I4 and coupler 64 isconnected to gear 20; in this case the torque line is from shaft 2,coupler 80, gear 14, gear 36, gear 31, gear 20, coupler 64 to shaft 3.Fourth speed is established when the coupler 80 is connected to gear2|)w and the coupler 64 is connected to the gear 20; in this conditionthere is a direct transmission of power from the shaft 2 to coupler 80to gear 20 to coupler 64 to shaft 3.

Reversespeeds are accomplished by shifting the gear 40 out of engagementwith gear 28 and into engagement with gear 43, it being remembered thatgear 44 is constantly connected to gear 28. The torque may betransmitted to shaft 35 either from gear l4 or gear 20 and the reverseto gear 26 to coupler 64 and to shaft 3. The couing a driving member anda driven member at different speed ratios and operable to change theratio while both members remain connected re-- spectively to driving anddriven mechanisms and both members are under torque load, two axiallyspaced elements connected to one of the members at different speedratios, a coupler slidably connected to the other member anddisposed-between the two said elements, co-operating teeth on oneelement and the coupler arranged to be dentally engaged and disengaged,co-operating teeth on 10 the other element and coupler arranged to bedentally engaged and disengaged, said coupler having an intermediateposition where both sets pf teeth are disengaged, the first mentionedcooperating teeth being disposed helically in a right hand manner, thesecond mentioned cooperating teeth being disposed helically in a lefthand manner, the right and left helical angle of the cooperating teethbeing such that the axial thrust on the coupler caused thereby upon thetransmission of torque is insumcient to overcome the combined loads onthe engaged teeth and on the siidable connection of the coupler, wherebydentaily engaged teeth'remain engaged upon torque reversal, means forapplying an axial force on the coupler for shifting the same axially toand from positions of dental engagement with the said two elements, andblocking means rendered effective by relative rotation between thecoupler and the element toward which the coupier is being urged by saidmeans for blocking movement of the coupler toward said element and whichis releasable as the relative rotation reverses for continued movementof the coupler toward the element to establish the dental engagevment,the helical direction of said teeth on the each element.

- ERNEST E. WEMP.

REFERENCES crrnn The followingreferences are of record in the file ofthis patent:

UNITED STATES PATENTS Robbins June 29, 1943

